Added WaitFor method on token interface.

Author: vincentparrett

Source/VSoft.CancellationToken.Impl.pas

@@ -46,6 +46,7 @@   TCancellationToken = class(TCancellationTokenBase, ICancellationToken, ICancel
     function GetEvent : TEvent;virtual;
     {$ENDIF}
     function  IsCancelled: boolean;virtual;
+    function WaitFor(Timeout: Cardinal): TWaitResult;virtual;
     procedure Cancel;virtual;
     procedure Reset;virtual;
   public
@@ -102,4 +103,9 @@ procedure TCancellationToken.Reset;
 end;
 
 
+function TCancellationToken.WaitFor(Timeout: Cardinal): TWaitResult;
+begin
+  result := FEvent.WaitFor(Timeout);
+end;
+
 end.

Source/VSoft.CancellationToken.pas

@@ -33,6 +33,9 @@ interface
   System.SyncObjs;
 
 type
+  //TDODO : use system.types if available.
+  TWaitResult = System.SyncObjs.TWaitResult;
+
   ///  ICancellationToken is passed to async methods
   ///  so that they can determin if the caller has
   ///  cancelled.
@@ -44,7 +47,7 @@ interface
     function GetEvent : TEvent;
   {$ENDIF}
     function  IsCancelled: boolean;
-
+    function WaitFor(Timeout: Cardinal): TWaitResult;
   {$IFDEF MSWINDOWS}
     //Note : do not call SetEvent on this handle
     //as it will result in IsSignalled prop